Conferencing systems and methods, in which participants communicate in a conference session or meeting over existing voice and data networks, have been in existence for some time. Recent examples of conference calling systems include U.S. Pat. No. 6,865,540, which teaches a method and apparatus for providing group calls via the Internet; U.S. Pat. No. 6,876,734, which teaches an Internet-enabled conferencing system accommodating public switched telephone network (PSTN) and Internet Protocol (IP) traffic; U.S. Pat. No. 6,931,001, which discloses a system for interconnecting packet-switched and circuit-switched voice communications; and U.S. Pat. No. 6,671,262, which teaches a system with conference servers for combining IP packet streams in a conference call into combined packet streams, such that the combined IP packet stream utilizes no more bandwidth than each of the original packet streams.
A variety of different features and approaches for scheduling, control, and management of conference call sessions are also known. For instance, a conferencing system that facilitates a conference call by enabling a participant in the call session to determine and categorize the identities of the other participants is taught in U.S. Pat. No. 6,931,113. A conference calling system in which each participant may individually control incoming audio streams from other participants, and in which participants may communicate privately with each other in the context of the conference call, is disclosed in U.S. Pat. No. 6,501,739. U.S. Pat. No. 6,816,469 teaches an IP telephony network and PSTN network that allows one or more call waiting callers to dynamically join in an existing multiple party conference call session.
In addition, commercially-available IP communication system products such as Cisco's MeetingPlace™ conferencing application allow users to schedule meeting conferences in advance or, alternatively, to set up conferences immediately by dialing out to participant parties. Cisco MeetingPlace™ is typically deployed on a corporate network behind the firewall, and facilitates scheduling of business conferences from a touch-tone or voice over IP (VoIP) telephone, or a computer, using various software clients, such as Microsoft® Outlook, or a web browser.
Often times during a meeting or conference session certain participants want to exchange messages or engage in discussions without disturbing the other participants of the conference session. For instance, in the middle of a conference session several participants may want to have a sidebar conversation to discuss some important topic. Existing conferencing systems such as Cisco's MeetingPlace™ software product allow a subset of meeting participants to enter a “breakout” session or “room” in which individuals can establish their own private communication group session apart from the main conference session by pressing a predetermined keypad code or sequence (e.g., by pressing #1(1-9)).
In a rich media conferencing system, such as where each of the conference participants are in front of a PC, then everyone can communicate using an instant messaging (IM) client or similar web-based tool to invite selected participants to enter a breakout session. However, for conference participants that have endpoints devices with non-rich media capabilities, such as audio-only endpoints, this is a problem. Using existing conferencing systems, the only practical way to invite a person with an audio-only endpoint device to join a breakout or sidebar session is to interrupt the conference discussions in order to ask that person to join the sidebar session. Naturally, this disturbs the other participants and interferes with the ongoing discussions. For privacy reasons it may also be desirable to keep others from knowing that the sidebar conversation is currently in progress.
What is needed therefore is a conferencing system and method that overcomes the drawbacks of the prior art and which enables audio-only endpoints to receive an invitation to participant in a sidebar session conference session without disturbing the other participants to the conference session.
By way of further background, a U.S. Pat. Nos. 6,608,820 and 6,236,854 teach methods for controlling a conference call that allows a controlling party using a mobile handset to engage in a private conversation with only one of the subject parties in a conference. A mobile station includes a store for storing a special conference call participant “set-up number” in relation to the subject party number and/or name. In addition, U.S. Pat. No. 5,729,687 describes a computer conferencing system having a plurality of participants coupled by a communication medium, each participant of the plurality of participants having a meeting manager, a process and apparatus for joining participants in the conferencing system.